The present invention relates to an emerizing apparatus including an emery-covered roller having multiple beater blades arranged about the periphery of the roller in parallel relation to its axis of rotation.
Emerizing machinery of the above-referenced type is known for working the surface of a textile web to provide a smooth napping of the web face. Typically, the textile web is guided to travel under tension, e.g. under a tractive force, with the web face to be napped in peripheral contact with the emery-covered roller, usually by means of guide rollers or rods contacting the web in advance of and following the emery-covered roller to tension the traveling web along the extent of its travel in contact with the emery-covered roller. The tractive force operating on the web is independent of the emery roller which may be rotated in a direction independent of the direction of travel of the textile web. The beater blades of the roller strike the surface of the web in a wiping-like manner, the abrasive nature of the emery covering of the roller raising the fibers of the web to produce a napped surface.
West German Gebrauchsmuster DE-GM 19 67 718 discloses an apparatus by which the surface fibers of a textile fabric web are loosened and raised to increase the web thickness. For this purpose, the apparatus is provided with one or more rollers each equipped with multiple beater blades for performing a beating and agitating operation on the web surface. In a preferred embodiment, multiple rollers are arranged in an arc and the fabric web is guided to travel in an essentially tangential path in succession over each of the rollers. In this manner, the surface yarns of the fabric web are loosened and raised by the striking action of the beater blades to provide a plush surface effect such as a velour, frotte, or the like.
In the textile industry, a practical distinction is drawn between emerizing machines and grinding machines. It is a characteristic of emerizing machines that the fabric web being treated is held against the surface of the emery roller or rollers of the machine by virtue of longitudinal tensioning of the fabric web itself. The emery roller, as aforementioned, includes beater blades about its periphery in parallel relation to its axis and is wound, preferably in a helical fashion, by an emery-covered belt. In contrast, textile grinding machines utilize a grinding roller the surface of which is coated entirely or in a predetermined pattern with a grinding agent. A representative grinding machine of this type is disclosed in West German Offenlegungschrift DE-OS 25 32 459. In a grinding machine, the textile fabric web to be treated is directed to travel through a nip region between the periphery of a grinding roller and a mating roller arranged in parallel peripheral engagement therewith. The present invention is intended for use primarily only with respect to emery-covered rollers utilized in emerizing machines.
In the operation of emerizing machines, the fabric web to be treated is guided by positioning rods or rollers to travel in contact with a predetermined portion of the circumferential periphery of the emery-covered roller, typically for about one-fourth of its circumference. In this manner, the web surface is contacted indirectly by the beater blades through the emery belt wrapped thereabout, whereby the beater blades exercise a wiping-like effect on the web surface.
It is recognized that the height of the nap raised at the web surface by the action of an emery roller in an emerizing machine is directly related to the period of time per unit length of the web during which the web is maintained in contact with the emery roller and, likewise, the density of the nap produced is directly related to the frequency with which the beater blades strike the fabric web per unit time. Accordingly, for any given emery-covered roller in an emerizing machine, relatively shorter and denser naps would be obtained at relatively higher rotational speeds of the roller, while relatively longer but less dense naps would be obtained at relatively lower rotational speeds of the roller. However, a critical rotational speed is associated with each emery roller according to its axial length at which speed the roller tends to oscillate and is incapable of producing a satisfactory working of a textile web. As will be understood, the roller and its mounting structure must be of a substantially stronger design than is required for normal operation if the critical speed is to be exceeded. In this regard, reference may be made to West German Patentschrift DE-PS 27 40 402.
In light of these considerations, it could be attempted to increase the number of beater blades on the circumference of an emery roller in order to achieve an increased number of web contacts per unit of time without increasing the rotational speed of the roller. However, practical limitations exist on the number of beater blades with which any given emery roller can be equipped. Because the roller rotation produces relatively high centrifugal forces, the beater blades must be securely fastened to the central axial body of the roller. Furthermore, while an increase in the number of beater blades would result in a corresponding increase in the number of contacts made by the beater blades with a textile web per unit of time without a change in the rotational speed of the roller, the duration of each individual contact changes only proportionally to the frequency of the contacts.